I've been running mine for ~4ish I think, on my third battery and might run out my fourth because it's feeling a _little_ sluggish at times.
I am waiting for the next FP model where I can use a USB-C/dp external display and then I'm all over it.
What is happening to your batteries? I'm on something like year 6 on my Redmi and my battery is fine. Am I simply lucky?
That's a lot, I usually use old phones from family members, most of them have 4 years of use by the time I get them and I get a whole day of usage from the battery.